Exosomes derived from human mesenchymal stem cells preserve mouse islet survival and insulin secretion function

Islet cell death and loss of function after isolation and before transplantation is considered a key barrier to successful islet transplantation outcomes. Mesenchymal stem cells (MSCs) have been used to protect isolated islets owing to their paracrine potential partially through the secretion of vascular endothelial growth factor (VEGF). The paracrine functions of MSCs are also mediated, at least in part, by the release of extracellular vesicles including exosomes. In the present study, we examined (i) the effect of exosomes from human MSCs on the survival and function of isolated mouse islets and (ii) whether exosomes contain VEGF and the potential impact of exosomal VEGF on the survival of mouse islets. Isolated mouse islets were cultured for three days with MSC-derived exosomes (MSC-Exo), MSCs, or MSC-conditioned media without exosomes (MSC-CM-without-Exo). We investigated the effects of the exosomes, MSCs, and conditioned media on islet viability, apoptosis and function. Besides the expression of apoptotic and pro-survival genes, the production of human and mouse VEGF proteins was evaluated. The MSCs and MSC-Exo, but not the MSC-CM-without-Exo, significantly decreased the percentage of apoptotic cells and increased islet viability following the downregulation of pro-apoptotic genes and the upregulation of pro-survival factors, as well as the promotion of insulin secretion. Human VEGF was observed in the isolated exosomes, and the gene expression and protein production of mouse VEGF significantly increased in islets cultured with MSC-Exo. MSC-derived exosomes are as efficient as parent MSCs for mitigating cell death and improving islet survival and function. This cytoprotective effect was probably mediated by VEGF transfer, suggesting a pivotal strategy for ameliorating islet transplantation outcomes

Ekspresija mRNA agutiju srodnog peptida i mRNA melanokortin-4 receptora u arkuatnoj jezgri za vrijeme gravidnosti i laktacije štakorica.

Pregnancy is associated with a range of physiological adjustments to adapt the body to the demands of the growth of the fetus and subsequent lactation. It has been observed that agouti-related peptide (AGRP) and melanocortin-4 receptor (MC4R) are involved in energy homeostasis. A randomized controlled experimental study was planned to investigate the expression of AGRP and MC4R mRNAs in the stages of pregnancy and lactation in rat arcuate nucleus (ARC) of the hypothalamus. Thirty-two adult female rats were randomly divided into six groups. Pregnant rats were assigned into three groups (n = 6) of 7, 14, and 21 days of pregnancy. Two more groups were also assigned of non-suckling rats (n = 5), immediately separated from their pups after parturition, and suckling rats (n = 5), allowed to suckle five pups until day 8 (increasing milk). The sixth group consisted of four ovariectomized rats, which were assigned two weeks after surgery and served as control. Using real-time PCR, the relative expressions (compared to controls) of MC4R and AGRP mRNAs in ARC were calculated in the pregnant, suckling and non-suckling rats. Expression of AGRP mRNAs in pregnant rats on days 14 and 21 was higher than that observed in suckling and non-suckling rats (P<0.05). Expression of MC4R mRNAs in pregnant rats on days 14 and 21 was lower than that observed in suckling rats, and was higher on day 7 than that observed in both suckling and non-suckling rats (P<0.05). In conclusion, expression of AGRP in pregnancy and MC4R in lactation in ARC of rats controls energy homeostasis.Gravidnost je povezana s nizom fizioloških prilagodbi kojima tijelo odgovara zahtjevima povezanima s rastom fetusa i kasnije laktacije. Uočeno je da su agutiju srodan peptid (AGRP) i melanokortin-4 receptor (MC4R) uključeni u energetsku homeostazu. Randomiziranim kontroliranim pokusom planirano je u arkuatnoj jezgri (ARC) hipotalamusa štakorica istražiti ekspresiju mRNA AGRP i mRNA MC4R tijekom gravidnosti i laktacije. Trideset dvije odrasle štakorice nasumično su bile podijeljene u šest skupina. Gravidne su štakorice podijeljene u tri skupine (n = 6), s obzirom na 7., 14. i 21. dan gravidnosti. Još dvije skupine (n = 5) činile su nedojne štakorice koje su odvojene od svoje mladunčadi odmah nakon porođaja te dojne štakorice kojima je dozvoljeno dojenje 5 mladunaca do osmog dana rastuće laktacije. Četiri ovarijektomizirane štakorice, dva tjedna nakon operacije, dodijeljene su u 6. kontrolnu skupinu. Koristeći PCR u stvarnom vremenu, relativna ekspresija (usporedba s kontrolama) mRNA MC4R i mRNA AGRP u ARC izračunata je za gravidne, nedojne i dojne štakorice. Ekspresija mRNA AGRP kod gravidnih štakorica 14. i 21. dan bila je veća od one opažene kod dojnih i nedojnih štakorica (P<0,05). Ekspresija MC4R mRNA u gravidnih štakorica 14. i 21. dan bila je manja u odnosu na dojne štakorica i veća 7. dan u odnosu na skupine dojnih i nedojnih štakorica (P<0,05). Zaključno, ekspresija AGRP u ARC tijekom gravidnosti i MC4R u ARC tijekom laktacije kontrolira energetsku homeostazu štakorica

Promjene u RF-amidu srodnom peptidu-3 hipotalamusa i ekspresijama gena Kiss1 tijekom spermatogeneze kod štakora u uvjetima kroničnog stresa.

The effects were evaluated of chronic stress and the glucocorticoid receptor antagonist (RU486) on mRNA expressions of RF-amide related peptide-3 (RFRP-3) in the dorsomedial hypothalamic nucleus (DMH) and Kiss1 in the arcuate nucleus (ARC) of male rats. Twenty-four male rats were allocated to four equal sized groups: the stress, RU486, stress/RU486, and control groups. In the stress group the rats were restrained 1 hour/day for 12 days. In the RU486 group, the rats were injected with RU486 for 12 days. In the stress/RU486 group, the rats were injected with RU486 1 hour before the stress process for 12 days. Relative expressions of RFRP-3 and Kiss1 mRNAs were determined using real-time PCR. The relative expression of RFRP-3 mRNA in the stress group was higher than that in the RU486 and control rats. The relative expression of RFRP-3 mRNA did not differ between the stress group and the stress/RU486 rats. Furthermore, the relative expressions of Kiss1 mRNA in the stress, RU486, and stress/RU486 groups were less than that of the control rats. The relative expression of Kiss1 mRNA did not differ between the stress, RU486, and stress/RU486 groups. In conclusion, dysfunction in male rat fertility caused by the chronic stress may be the result of the increase in REFP-3 and the decrease in Kiss1 mRNA expression.Istražen je učinak kroničnog stresa i antagonista glukokortikoidnog receptora (RU486) na ekspresiju mRNA RF-amidu srodnog peptida-3 (RFRP-3) u dorzomedijalnoj jezgri hipotalamusa (DMH), te na ekspresije gena Kiss1 u arkuatnom nukleusu (ARC) štakora. Dvadeset i četiri štakora bila su raspodijeljena u četiri jednake skupine: stresna skupina, RU486 skupina, stresna/RU486 skupina i kontrolna skupina. U stresnoj skupini štakori su 12 dana bili obuzdani tijekom jednog sata dnevno. U skupini RU486, štakorima je tijekom 12 dana bio primijenjivan RU486. U skupini stres/RU486, štakorima je tijekom 12 dana apliciran RU486 jedan sat prije postupka obuzdavanja. Relativne ekspresije RFRP-3 i Kiss1 mRNA određene su lančanom reakcijom polimerazom u stvarnom vremenu. Relativna ekspresija RFRP-3 mRNA u stresnoj skupini bila je veća nego u skupini RU486 i kontrolnoj skupini. Relativna ekspresija RFRP-3 mRNA nije bila različita između stresne skupine i stres/RU486 skupine. Nadalje, relativne ekspresije Kiss1 mRNA u stresnoj skupini, skupini RU486, i stresnoj skupini/RU486 bile su manje u odnosu na kontrolnu skupinu. Relativna ekspresija Kiss1 mRNA nije se razlikovala između stresne skupine, skupineRU486 i stresne skupine/RU486. Zaključno, disfunkcija plodnosti kod štakora izloženih kroničnom stresu može biti uzrokovana putem povećane ekspresije RFRP-3 i smanjene ekspresije Kiss1 mRNA

Expression of melanocortin-4 receptor and agouti-related peptide mRNAs in arcuate nucleus during long term malnutrition of female ovariectomized rats

Objective: Melanocortin-4 receptor (MC4R) and agouti-related peptide (AgRP) are involved in energy homeostasis in the rat. The aim of the present study was to evaluate the expression of MC4R and AgRP mRNAs in arcuate nucleus (ARC) during long term malnutrition of female ovariectomized rats. Materials and Methods: Ten female ovariectomized rats were divided into two equal groups (n=6) of normal and restricted diet groups. Using real-time PCR, the relative expressions (compared to controls) of MC4R and AgRP mRNAs were compared between both diet groups. Results: The relative expression of MC4R and AgRP mRNA in the ARC of female ovariectomized rats during long term malnutrition was higher than those with normal diet (

Ekspresija mRNA agutiju srodnog peptida i mRNA melanokortin-4 receptora u arkuatnoj jezgri za vrijeme gravidnosti i laktacije štakorica.

Pregnancy is associated with a range of physiological adjustments to adapt the body to the demands of the growth of the fetus and subsequent lactation. It has been observed that agouti-related peptide (AGRP) and melanocortin-4 receptor (MC4R) are involved in energy homeostasis. A randomized controlled experimental study was planned to investigate the expression of AGRP and MC4R mRNAs in the stages of pregnancy and lactation in rat arcuate nucleus (ARC) of the hypothalamus. Thirty-two adult female rats were randomly divided into six groups. Pregnant rats were assigned into three groups (n = 6) of 7, 14, and 21 days of pregnancy. Two more groups were also assigned of non-suckling rats (n = 5), immediately separated from their pups after parturition, and suckling rats (n = 5), allowed to suckle five pups until day 8 (increasing milk). The sixth group consisted of four ovariectomized rats, which were assigned two weeks after surgery and served as control. Using real-time PCR, the relative expressions (compared to controls) of MC4R and AGRP mRNAs in ARC were calculated in the pregnant, suckling and non-suckling rats. Expression of AGRP mRNAs in pregnant rats on days 14 and 21 was higher than that observed in suckling and non-suckling rats (P<0.05). Expression of MC4R mRNAs in pregnant rats on days 14 and 21 was lower than that observed in suckling rats, and was higher on day 7 than that observed in both suckling and non-suckling rats (P<0.05). In conclusion, expression of AGRP in pregnancy and MC4R in lactation in ARC of rats controls energy homeostasis.Gravidnost je povezana s nizom fizioloških prilagodbi kojima tijelo odgovara zahtjevima povezanima s rastom fetusa i kasnije laktacije. Uočeno je da su agutiju srodan peptid (AGRP) i melanokortin-4 receptor (MC4R) uključeni u energetsku homeostazu. Randomiziranim kontroliranim pokusom planirano je u arkuatnoj jezgri (ARC) hipotalamusa štakorica istražiti ekspresiju mRNA AGRP i mRNA MC4R tijekom gravidnosti i laktacije. Trideset dvije odrasle štakorice nasumično su bile podijeljene u šest skupina. Gravidne su štakorice podijeljene u tri skupine (n = 6), s obzirom na 7., 14. i 21. dan gravidnosti. Još dvije skupine (n = 5) činile su nedojne štakorice koje su odvojene od svoje mladunčadi odmah nakon porođaja te dojne štakorice kojima je dozvoljeno dojenje 5 mladunaca do osmog dana rastuće laktacije. Četiri ovarijektomizirane štakorice, dva tjedna nakon operacije, dodijeljene su u 6. kontrolnu skupinu. Koristeći PCR u stvarnom vremenu, relativna ekspresija (usporedba s kontrolama) mRNA MC4R i mRNA AGRP u ARC izračunata je za gravidne, nedojne i dojne štakorice. Ekspresija mRNA AGRP kod gravidnih štakorica 14. i 21. dan bila je veća od one opažene kod dojnih i nedojnih štakorica (P<0,05). Ekspresija MC4R mRNA u gravidnih štakorica 14. i 21. dan bila je manja u odnosu na dojne štakorica i veća 7. dan u odnosu na skupine dojnih i nedojnih štakorica (P<0,05). Zaključno, ekspresija AGRP u ARC tijekom gravidnosti i MC4R u ARC tijekom laktacije kontrolira energetsku homeostazu štakorica

Hypoxia-Preconditioned Wharton’s Jelly-Derived Mesenchymal Stem Cells Mitigate Stress-Induced Apoptosis and Ameliorate Human Islet Survival and Function in Direct Contact Coculture System

Protection of isolated pancreatic islets against hypoxic and oxidative damage-induced apoptosis is essential during a pretransplantation culture period. A beneficial approach to maintain viable and functional islets is the coculture period with mesenchymal stem cells (MSCs). Hypoxia preconditioning of MSCs (Hpc-MSCs) for a short time stimulates the expression and secretion of antiapoptotic, antioxidant, and prosurvival factors. The aim of the present study was to evaluate the survival and function of human islets cocultured with Hpc-MSCs. Wharton’s jelly-derived MSCs were subjected to hypoxia (5% O2: Hpc) or normoxia (20% O2: Nc) for 24 hours and then cocultured with isolated human islets in direct and indirect systems. Assays of viability and apoptosis, along with the production of reactive oxygen species (ROS), hypoxia-inducible factor 1-alpha (HIF-1α), apoptotic pathway markers, and vascular endothelial growth factor (VEGF) in the islets, were performed. Insulin and C-peptide secretions as islet function were also evaluated. Hpc-MSCs and Nc-MSCs significantly reduced the ROS production and HIF-1α protein aggregation, as well as downregulation of proapoptotic proteins and upregulation of antiapoptotic marker along with increment of VEGF secretion in the cocultured islet. However, the Hpc-MSCs groups were better than Nc-MSCs cocultured islets. Hpc-MSCs in both direct and indirect coculture systems improved the islet survival, while promotion of function was only significant in the direct cocultured cells. Hpc potentiated the cytoprotective and insulinotropic effects of MSCs on human islets through reducing stressful markers, inhibiting apoptosis pathway, enhancing prosurvival factors, and promoting insulin secretion, especially in direct coculture system, suggesting the effective strategy to ameliorate the islet quality for better transplantation outcomes